Application of pre-fishery abundance modelling and Bayesian hierarchical stock and recruitment analysis to the provision of precautionary catch advice for Irish salmon (Salmo salar L.) fisheries

Abstract

abundance modelling and Bayesian hierarchical stock and recruitment analysis to the provision of precautionary catch advice for Irish salmon (Salmo salar L.) fisheries. e ICES Journal of Marine Science, 61: 1370e1378.Ireland has one of the last remaining commercial salmon driftnet fisheries in the North Atlantic, with recent catches averaging 162 000 salmon (1997e2003), approximately 20% of the total landings of salmon in the entire North Atlantic. Since 2001, the Irish commercial salmon fishery has been managed on the basis of Total Allowable Catch (TAC) in each of 17 salmon fishing districts. This has been made possible by applying a number of new and innovative techniques to the estimation of conservation limits (CLs) and prefishery abundance (PFA) for combined stocks in each district. Stock and recruitment parameters from well-monitored European rivers were ''transported'' to all Irish rivers using a Bayesian hierarchical stock and recruitment (BHSRA) model. This provided the posterior probability distributions of the model parameters and related reference points, including individual river CLs. District PFA and the number of spawners were estimated for a baseline period of 1997e2003, using district catch data, estimates of unreported catch, and exploitation rate. Harvest guidelines were established on the basis of surplus of spawning fish over the CL for the baseline period. In line with scientific advice, the commercial fishery has been reduced from 212 000 fish in 2002 to 182 000 in 2003. In 2004, a total catch (including the rod catch) of approximately 160 000 wild salmon was advised.

Impact of early infestation with the salmon louse Lepeophtheirus salmonis on the subsequent survival of outwardly migrating Atlantic salmon smolts from a number of rivers on Ireland's south and west coasts

“…Information on capture location and return data of the experimental groups was gathered as part of an ongoing Irish national coded wire tag recovery programme (Browne et al, 1994;Ó Maoiléidigh et al, 2004). Catches from coastal commercial fisheries (drift nets, draft nets, etc.)…”

Impact of Lepeophtheirus salmonis infestations on migrating Atlantic salmon , Salmo salar L., smolts at eight locations in Ireland with an analysis of lice‐induced marine mortality

“…Declines in marine survival of Atlantic salmon have been recorded in Ireland (Salmon Management Task Force Report (Anon. 1996); Ó Maoiléidigh et al . 2004; Jackson et al .…”

Spatial distribution of Atlantic salmon (Salmo salar) breeders: among- and within-river variation and predicted consequences for offspring habitat availability

“…The management of Atlantic salmon is to an increasing degree being based on the identification of spawning targets (ST), representing the number of spawners (and by extension eggs) required for different populations to satisfy some desired recruitment strength (e.g., Ó Maoiléidigh et al 2004;Chaput et al 1998;Hindar et al 2007). Because identification of STs is based on empirical stock-recruitment relationships, and such data are absent for most populations, one of the main challenges for management is to transfer knowledge from data-rich to data-poor rivers.…”